Project Summary While the widespread use of highly active antiretroviral therapy has markedly decreased cardiac morbidity and mortality in perinatally HIV-infected children, several studies have suggested subclinical abnormalities in echocardiographic measures of left ventricular structure and function. The goal of this study is to longitudinally evaluate the cardiovascular status of perinatally HIV-infected adolescents and young adults and to explore whether chronic inflammation and/or mitochondrial abnormalities are associated with echocardiographic and biomarker changes over time. The specific aims of this study are to 1) to determine longitudinal changes of cardiovascular risk factors that were assessed ~6 years ago in the AMP (adolescents) and AMP Up (young adults) perinatally HIV-infected (PHIV) and HIV-exposed, uninfected (PHEU) cohorts of the Pediatric HIV/AIDS Cohort Study (PHACS); and to measure modified Pathobiological Determinants of Atherosclerosis in Youth or PDAY scores (a measure of aggregate cardiovascular risk) in HIV-infected adolescents longitudinally; and 2) To determine the role of systemic mitochondrial dysfunction in cardiovascular abnormalities and biomarkers by assaying mitochondrial DNA (mtDNA) copies/cell, oxidative phosphorylation (OXPHOS) enzyme activities, oxygen consumption (respiration), and mitochondrial oxidative stress. The results of this study can identify if there are perinatally HIV-infected adolescents and young adults, with long term exposure to HAART, which are at increased risk of future cardiovascular morbidities. If this is the case, the results of this study can inform various interventions in this increased cardiovascular risk group to decrease their future risk of adverse cardiovascular events.